How to Fit a Door Knob with Concealed Fixings

Author: Carl Benson

Carl is the founder of Suffolk Latch Company, with a background in engineering and over 20 years’ experience in home hardware. He works closely with suppliers and designers alike to develop quality ironmongery that stands the test of time. Read my full bio.

Door knobs with concealed fixings are an ideal choice if you want a neat design without visible screws or fixings.

Watch our video and follow our step-by-step door knob fitting guide below for advice on fitting this style of door knob.

If you are looking for advice on fitting a door handle with concealed fixings, view our dedicated concealed door handle fitting video.

Unboxing Your Door Knob

When your pair of door knobs arrives, the knobs will usually be fixed onto the mortice bar. The first step is to separate the component parts ready for installation.

In this example, we are using the solid brass Mushroom door knob in a distressed silver finish from our Old English Collection.

The parts are as follows:

• Pair of solid brass Mushroom door knobs with fixed rose plates.
• 8mm mortice bar.
• Inner rose plates plus plastic washers.
• Fixing screws.

You can remove the door knobs from the mortice bar by using the Allen key to loosen the grub screw. The grub screw is housed inside a small hole on the neck of the door knob.

The Mortice Bar

The mortice bar is an 8mm metal bar that passes through the door. Each door knob is fixed to the mortice bar on either side of the door.

The mortice bar in our example has a split at both ends with a grooved indent. This helps the grub screw grip securely as it is tightened onto the bar.

The Inner Rose Plate

This type of door knob uses an inner or hidden rose plate with fixing holes. This allows the door knob to be fixed to the face of the door while keeping the screws concealed.

A plastic washer is also included to help prevent looseness once the knob is fitted. The inner rose plate should be unscrewed from the door knob before installation.

Step-by-Step Guide to Fitting a Door Knob with Concealed Fixings

• Insert the 8mm mortice bar spindle into the pre-drilled bore hole in your door and through the tubular latch. For guidance on fitting tubular latches, read our tubular latch fitting guide.
• Place the inner rose plate over each end of the mortice bar so that it sits flush against the face of the door.
• Fit the plastic washer in place.
• If your door knob has bolt-through fixings, make sure the correct pilot holes have been drilled and that they line up with the bolt-through fixings on your architectural tubular latch.
• For face-fixing inner rose plates, pre-drill the pilot holes and fit the rose plates using the screws provided. Please note: door thicknesses can vary, so take care not to damage the latch when tightening the screws.
• Fit the door knob with its fixed outer rose plate onto the mortice bar, then screw it onto the inner rose plate until it sits tight against the surface of the door.
• Make sure the grub screw hole lines up with the grooved slit on the mortice bar.
• Tighten the grub screw using the Allen key.

Your door knob is now fitted and ready for use.

We hope you found this guide helpful. If you have any questions, please contact us for advice.

You may also find our guides on fitting a reversible tubular latch and how to hang a door useful.